1. Field of the Invention
The present invention relates to a multi-lens camera and a control method. More particularly, the present invention relates to a multi-lens camera of which plural images are created with parallax, and misalignment between plural lens systems can be eliminated easily and exactly, and a control method for control of the same.
2. Description Related to the Prior Art
A dual lens camera as multi-lens camera for producing a three-dimensional image by combining plural images with parallax is known, and includes plural lens systems. To obtain the three-dimensional image of good quality in the dual lens camera, misalignment other than suitable parallax between the images should be suppressed in the lens systems. However, skew may occur with optical axes of the lens systems due to various reasons such as errors in dimensions of parts, errors in assembly and the like. The misalignment will occur unacceptably due to the skew of the optical axes. There have been a number of suggestions in the dual lens camera for preventing the misalignment of the plural images in occurrence of skew of the optical axes of the lens systems.
In JP-A 2003-052058, image registration for the images is disclosed in which positions of reading the images are adjusted according to a displacement amount between a center of an image pickup device and a center of the optical axes of the lens systems, to read only positions corresponding between the images. In JP-A 6-054349, a mechanism for shifting the optical axes is disclosed to adjust a direction of the optical axes in the lens systems in relation to an elevation angle direction, azimuthal angle direction, and horizontal direction. Image registration is carried out for the images by regulating the optical axes of the lens systems by the shifting mechanism. In U.S. Pat. Nos. 7,102,686 and 7,667,768 (corresponding to JP-A 11-355624), a cross shaped key is used to input information of a direction and amount of shift finely to adjust the position and angle of the images. Limited portions are retrieved from image frames of the images according to the direction and amount of the shift, to remove the misalignment for the image registration.
A zoom mechanism is additionally incorporated in each of the lens systems. An amount of correcting the misalignment is different according to a zoom position (focal length) of the lens systems. It is necessary to carry out image registration by adjustment for each of the zoom positions of the lens systems in the structure with the zoom mechanism in the lens systems, to complicate the operation excessively.
Generally, a manufacturer of the dual lens camera carries out the image registration in the manufacture to suppress the misalignment of plural images. Among numerous users or operators purchasing the dual lens camera, somebody may be unfamiliar to manual handling of mechanical parts, and will not carry out the image registration successfully by himself or herself. However, the image registration on the side of the manufacturer is suitable for the user of the dual lens camera to use the dual lens camera easily and sufficiently to obtain the three-dimensional image without noticing the misalignment of the plural images.
However, an accident may occur to give extraordinary shock to the dual lens camera typically when the user drops or strikes the dual lens camera. The misalignment is likely to occur with images as the optical axes of the lens systems may skew no matter how exactly the dual lens camera has been conditioned and adjusted by the manufacturer. If a user or operator uses the dual lens camera during a trip or under other unfamiliar conditions, it is very difficult to have the manufacturer to repair the dual lens camera. It is preferable practically for the user to correct the misalignment of the images by readjustment for image registration. The image registration with difficulties is not acceptable so that he or she may give up in continuous use of the dual lens camera. Also, difficult operation for the image registration will result in failure to cause the misalignment to remain after the readjustment. There is no suggestion of correcting the misalignment of the images by readjustment easily to end users who may be unskilled in mechanical operation.